Again, If you have left yourself no way to prove it, how do you prove it? Try doing spot checks at the polls and see what you come up with.

You don't have to do that. Here's what you do: purchase the voting rolls afterwards. This will show you who voted in the district. Then actually go to every person on the roll and see if they voted. If they say no, then you know there was in-person voter fraud.

How much of the voting process is a complete mystery to you, by the way?